1. Field of the Invention
The present invention relates to the manufacturing of chairs, and more particularly to a method for efficiently manufacturing chairs having customizable backs.
2. Related Art
The introduction of chairs into Western Civilization is a relatively recent event as compared to the overall history of the Western world. Eastern cultures have only embraced chairs as a commonly used piece of furniture in recent decades by comparison. Indeed, there are still nomadic and rain forest cultures, among others, that do not employ chairs as we known them. In any event, the usefulness of the simple chair is often overlooked since it is so commonplace now and little thought is normally given to its origins or design.
Perhaps one reason why chairs arise later in the history of human culture may lie in the complexity involved in chair design. Again, this complexity is not often realized since chairs and chairs of many different design types are ubiquitous in modern societies. However, when one considers the loading and function of a chair, the design attributes are revealed. When a person sits in a chair, a load is distributed through the seat and back portions into the frame of the chair where it is eventually transmitted to the floor upon which the chair (and now the occupant) sits. This relationship between the components of a chair system is a dynamic environment that requires a solid understanding of the parametrics of chair design. Failure to observe these parameters is likely to result in wasted efforts and materials, as the chair manufacture will be producing furniture that will routinely fail when used.
As may be appreciated, early chair designs relied upon wood components and since these could be found in abundance, chair designs were generally robust and resulted from trial and error approaches. As modern construction materials became available, however, the use of steel, aluminum, stainless steel, and other alloys provided for greater strength in lighter frames of lesser overall substance. The upsurge in this type of chair design hit a stride in the 1950s with the increasing popularity of metal office and commercial furniture products. In these years, however, even the frames tended to be the result of overkill and were many times made so bulky or weighty that they were not well received by all potential users.
Modern chairs have the advantage of proven frame designs that utilize minimized and refined frames compared to the early types of metal based chairs. This has made the frame based chair design very popular for industrial, commercial and residential applications. Such frame chairs are usually found with complementary seat and back portions that may be made from wood, plastic or metal, and which may be finished or which may be upholstered with fabrics and the like. This frame chair is the predominant type of chair especially in industrial and commercial uses, and versions of the frame chair have merged well with residential uses as well. Since the frame for the chair can be reproduced using mass manufacturing techniques, large numbers of chairs can be produced at very reasonable cost. The downside, however, is that the variability in the final cosmetic appearance of the frame chair is limited as a result of this prior art manufacturing methodology leading to a product that is typically offered in one configuration with perhaps a number of different finishes and/or colors. This limitation will many times reduce the desirability of the frame chair where people are looking to purchase seating for their restaurants, offices, schools, or other applications and want to match an existing or proposed décor or where the desire is merely to have something distinguished from the catalog of mass manufactured options.
In U.S. Pat. No. 5,227,476 (Caldwell), a modular chair design is shown where the seat and back portions of the chair are independently associated with the “frame” of the chair and are easily assembled by the user. This modular chair design is predicated upon a substantial frame, preferably fabricated from wood components, and does not suggest a modular chair approach where customization of back and seat portions can be accomplished in the context of a mass production environment. Similarly, in U.S. Pat. No. 5,795,028 (Dussia, Jr. et al) an easy chair design is shown as being built up from a sub-frame, however this design is reliant on substantial componentry and does not teach a way to customize a frame chair in a mass manufacturing context.
U.S. Pat. No. 3,870,366 (Rogers) discloses a knock-down modular type of chair based on wood components. All of the components, including the frame, the seat and the back, are independent and are assembled as a kit. This reference does not teach a frame chair of a modular design type that can be fitted with an unlimited number of customized back and/or seat portions.
Furthermore, it is known in the chair making art to provide customers with a limited ability to customize certain aspects of a chair. For example, chair finish can be made to customer order, as well as various engraving or upholstering finishes. These prior art techniques are fairly limited, however, such that a designer has not the freedom to create interesting new shapes and chair profiles.
There exists therefore a longstanding need in the chair making industry, where a chair assembly can be more fully customized to a designer's intent without diminishing structural integrity or unduly affecting production speed.